====== Raspberry Pi B+ als (Zeitraffer) Kamera ======
===== Quellen: =====
  * [[https://www.raspberrypi.org/documentation/linux/usage/cron.md|Cron Jobs einrichten]]
  * [[https://lonewolfonline.net/raspberry-pi-timelapse-videos/|JPG-Bilder zusammenfügen]]

===== Basissystem =====
  * Installation des Basissystems - Raspberri OS aka. Debian Buster vom 04.03.2021

===== Kamera testen - einzelne Aufnahme auslösen =====
<code bash>
# get image directly from camera:
christoph@christophs-nb:~$ ssh pi@raspberry-test-wlan 'raspistill -o cam.jpg'; DATE=$(date +"%Y-%m-%d_%H%M"); scp pi@raspberry-test-wlan:~/cam.jpg $DATE.jpg
</code>

===== USB-Stick einbinden =====
<code bash>
sudo su
echo "/dev/sda1  /mnt/sda1               ext4    defaults,noatime  0       1" >> /etc/fstab
</code>

===== Bilder aufnehmen =====
<code bash>
pi@raspicam:~ $ cat time-laps.sh 
#!/bin/bash
#
#FOLDER=/home/pi/time-laps
#FOLDER=/mnt/sda1/time-laps
DATE=$(date +"%Y%m%d")
echo "DATE: $DATE"
TIMESTAMP=$(date +"%Y-%m-%d_%H%M")
echo "TIMESTAMP: $TIMESTAMP"
FILE=$TIMESTAMP.jpg
echo "FILE: $FILE"
FOLDER="/mnt/sda1/$DATE"
echo "FOLDER: $FOLDER"

if [ -d $FOLDER ]; then
 echo "Folder $FOLDER already exist!"
else
 mkdir $FOLDER
fi

echo -n "take a picture and store it to: $FOLDER/$FILE ... "
raspistill -o "$FOLDER/$FILE"
echo "done"
</code>

===== Automatische Aufnahmen via CRON Job =====
<code bash>
crontab -e
...
# execute every 5 minutes between 07:00 and 20:00 am:
*/5 7-19 * * *  /home/pi/time-laps.sh
</code>
Check ''crontab'' for user ''pi'':
<code bash>
sudo su
cat /var/spool/cron/crontabs/pi
</code>

===== Aufnahmen vom Pi holen =====
<code bash>
christoph@christophs-nb:~$ DATE=20210408; mkdir $DATE; scp pi@raspberry-test-wlan:/mnt/sda1/$DATE/* $DATE/
</code>


===== Zeitraffer erstellen =====
<code bash>
ffmpeg -r 30 -pattern_type glob -i "*.jpg" -c:v libx264 -pix_fmt yuv420p -movflags +faststart timelapse.mp4
</code>